theodor steestwat



(Ne Model.)

Cgi-F'. TrS-T-EVINWAY. Y Y Screw Clamp for Wood Bending Machin-es. No. 229,198. x4' Patented v.lune 22, 1880',

N.PEERS, PHOTUJJTIIOGMPNER. WASHINGTON, D, C,

NITED STATES PATENT EEICE.

SCREW-CLAMP `Fon woon-BENDING MACHINES.

SPECIFICATION forming part of Letters `Patent No. 229,198, dated Tune 22, 1880.

Application tiled March 10, 1880. (No model.)

` Clamps for Wood-BendingApparatus, of which the following is a specication.

My improvements relate to that class of wood-bending apparatus in which screw- Y clamps are used to hold an object against the curved face of a former or templet; and my invent-ion consists, broadly, in the employment of links, preferably constructed of dat bariron,for connecting the clamp-pins, which are inserted transversely through the templet or former, respectively, with the bars through which the clamp-screws are inserted.

One important object of my improvements is to facilitate the bending ofthe rims of pianoframes upon a short radius, and I have therefore devised links of tapering form, the narrower ends of which are hooked on the pins which pass transversely through the templet, while the larger ends embrace the screw-clamp bar.

Heretofore clamps of this character have been made principally of wood, and the neeessary size of the wooden links connecting the screw-clamp bar with. the former has been such Aas to prevent the clamps from bein g placed sufficiently near together to act conjunctively upon a short curve. By my invention, owing to the tapering of the links, I am enabled to set the clamps closer together, and hence to employ a greater number of clamps for holding a plank or rim bent upon a short radius.

That part of my invention which resides in the tapering links may be carried out by giving an inwardly-tapering form to the object,

whatever it may be, which connects the screw-V taper-link clamps. Fig. 2 is a transverse section ofthefcrmer and one of theclamps through the line x .r on' Fig. l. Fig. 3 is a transverse section of the screw-clamp bar through the line y y on Fig. 2. Fig. 4 is a transverse section of a screw-clamp bar composed of two metallic tubes, one inside the other, Figs. 3

and 4 being drawn on an enlarged scale for clearness of illustration.

In the drawings, a templet or former, A, of the shape required for forming the rim of a piano-frame, is, it will be seen, provided with a series ot' transverse holes, a, for the reception of the clamp-pins B. Each of these pins,

it will be observed, projects sufficiently froml screws d are transversely inserted. The clamp,

therefore, considered by itself, consists of a screw-clamp bar, D, and a clamp-pin, B, linked together by the two tapering links G C, which, in operation, are applied one on one side and the other on the other side of the templet or former.

I use, preferably, iron tubes for both the pins and the screw-clamp bar, and tightly ll the interior of these tubes with hard wood.

I may also use in the construction of the screw-clamp bar two tubes, or a nest of tubes, one inside the other, as shown in Fig. 4; but I have found that for ordinary purposes sufficient rigidity is obtained by the employment of a single metallic tube filled with hard wood; and a part ot' my invention consists in. a screwclamp bar composed of a metallic tube completely filled with wood.

For the purpose of thus filling the tube, I turn a cylinder of wood to fit the interior of the tube, and then cut out a longitudinal section of the cylinder, and having inserted the two segments in the iron tube, I then drive between them a tongue of Wood slightly thicker than the section which has-been removed, as shown in Fig. 3, in which the two wooden segvments E Ef are represented as being tightly held in the tube by the interposed tongue F, which has been driven in between them.

My clamp-screws d have the usual square threads, and are inserted transversely through IOO the clamp-bar D, and are engaged by female threads formed in the saddle g, which is permanentlysecured to the clamp-bar D by means ofthe screws g. The sides g2 of the saddle converge toward the former, and the bearing of the links upon these converging sides prevents the lateral tilting ofthe clamp, and preserves the proper alignment of the clampscrews with the center of the pin inserted through the former.

I employ in connection with my clamps a shield, H, which receives the impact of the clamp-screws and transmits their thrust to the plank or rim I, which is interposed between the shield and the periphery of the former while undergoing the process of bending.

I preferably build up my former or templet of several layers of planks glued together', with the grain of the wood of the several layers arranged in relatively different directions, and I may' surround the periphery of the former with the iron plate A.

Iron ferrules a may, it' desired, be inserted in the holes a for the reception of the clamppins B. rlhis, however, will not be necessary eXcept for adapting the apparatus for bending very thick planks.

In operation, my clamps are readily applied by hooking the smaller end of the links over the two projecting ends of the clamp-pins and the larger ends of the links over the opposite ends of the clamp-bars, and then turning the clamp-screws against the shield, which bears upon the exterior surface of the object which is being bent. When the bending operation is completed the object operated upon is easily detached by turning back the clamp-screws and removing one set of links.

I claim as my invention in apparatus for bending woodl. A detachable clamping device for application to a former, the said device consisting of two metallic bars and two removable taper-l and presenting upon its sides, near the end of the clamp-bar, two relatively-inclined surfaces, in combination with the tapering metallic link C, the sides of which are afforded bearings upon the said relatively-inclined surfaces, substantially as and for the purpose set forth. C. F. THEODOR STEINWAY. Vitnesses:

M. L. ADAMS, GEO. W. MIATT. 

